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Altering the Crawler Java Classpath

The Ultra Search crawler is a pure Java application that runs in a Java virtual machine. A Java virtual machine uses the Java classpath to find classes during runtime. When Ultra Search is installed, the default crawler classpath is stored in the database. Whenever a new Ultra Search instance is created, this default classpath is copied and used as the crawler classpath for that specific instance.

Reasons for Altering the Crawler Java Classpath

Usually, you do not need to alter the crawler Java classpath. However, there may be certain reasons for you to do so. One reason could be to replace the JavaMail™ reference implementation with a third party JavaMail implementation.

Difference Between the Crawler Classpath and the Remote Crawler Classpath

The crawler classpath is the classpath of a crawler that runs on the same host that the Ultra Search Server component is installed. However, Ultra Search allows remote crawlers to be run on other hosts for scalability.

Remote crawler activation uses Java remote method invocation (RMI) technology. As a result, the classpath setting of a remote crawler is inherited from the classpath settings of the RMI registry and RMI daemon.

See Also: Appendix C, "Using the Remote Crawler"

Altering the Crawler Java Classpath on the Ultra Search Server Host

1. Log on to the host where the Ultra Search Server component is installed. Locate the file $ORACLE_HOME/ultrasearch/admin/wk0cpath.sql.
2. Using SQL*Plus, run the wk0cpath.sql script as the WKSYS superuser or as a database user that has been granted the WKADMIN role.
3. When prompted, specify whether you want to alter the default classpath or an instance-specific classpath. Altering the default classpath causes all subsequently created instances to use that classpath. Existing instances are not modified.
4. When prompted, enter the Ultra Search instance name if you are attempting to modify an instance-specific classpath. If you are modifying the default classpath, you do not need enter anything here.
5. When prompted, specify whether you want to update the entire classpath or append to it. Appending to a classpath adds entries to the beginning of it. Usually, entries earlier on in the classpath override later entries in the case of duplicate classes.
6. When prompted, enter the new classpath if updating the entire classpath. If you are appending one or more directories or library files to the classpath, then enter these separated by the classpath separator for the platform where the Ultra Search Server component is installed (the colon on UNIX platforms, or the semicolon on Windows).

Altering the Crawler Java Classpath on a Remote Crawler Host

1. Log on to the host where the Ultra Search middle tier components are installed on a remote crawler host. If the host is a UNIX machine, locate the file $ORACLE_HOME/ultrasearch/tools/remotecrawler/scripts/unix/define_env. If the host is a windows NT machine, locate the file $ORACLE_HOME/ultrasearch/tools/remotecrawler/scripts/winnt/define_env.bat.
2. The define_env file specifies all environment settings used by the RMI subsystem. To alter the classpath, use a text editor to modify the APPLICATION_CLASSPATH variable.
3. You must restart the RMI subsystem before these changes can take effect.

   See Also: Appendix C, "Using the Remote Crawler" for more details on starting up the RMI subsystem